You would think it would be a little intimidating. But for this tiny chihuahua, having a best friend 120 times his size is proving a great source of comfort.

The diminutive Digby was abandoned on the street next to a set of bins. At just over a month old and weighing less than 1lb, he was freezing cold and perilously close to death.

Fortunately, he was rescued by the RSPCA and taken to their Southridge centre in Hertfordshire - where he quickly became inseparable from 9st mastiff Nero.

New pals: Tiny chihuahua Digby with best friend Nero, a 9st mastiff who is 120 times the size. Digby was rescued by the RSPCA and taken to a centre in Hertfordshire where the two have quickly become inseparable

'It was as if the little fellow took on Nero as his personal minder,' said centre manager Anna White.

'Poor Digby had to be rescued once by the RSPCA and it seems like he is taking precautions to make sure nothing can happen to him again.'

Digby was found severely dehydrated and cowering between two bins at a block of flats in North London last week. But he was revived by the reassuring presence of the mastiff, who eats more than Digby's weight in pet food each day.

Natalie Ditchfield, RSPCA animal collection officer, said: 'It is so lovely to see he is safe and happy.

'Love story': Digby was found severely dehydrated and cowering between two bins at a block of flats in North London. But staff at the RSPCA say he has been revived and come out of his shell after finding Nero

'When I first came across Digby he was frozen and shaking and had just been left to die. He's really tiny - small enough to fit in the palm of my hand.

'He seemed to come out of his shell as soon as we arrived at Southridge and spotted Nero. It really is a love story.'

The RSPCA is appealing for information in a bid to trace Digby's owner. Unless one comes forward, he will be available for rehoming in the coming days.